If this mistake has incurred you the financial loss of 15k then you're entitled for the compensation of 15k exclusively.
Besides that, you can further, demand more compensation for loss of time, harrasment & mental anguish, because of the deficiency of Axis.
So, compensation of 15k +...(put some reasonable amount for non financial loss). You may think what's reasonable? No one can answer it. What you think put it, let us know what're you going to put, then we can comment further based on our....
You're rightfully entitled for it. Don't settle for Melodrama.
You have documentary evidences of all the communication/ conversation, that's more than enough, not required to wait 30 days, 30 days is when you're not getting any reply, you already got unsatisfactory one. Do you have ticket/case ID? Hope, you have recorded call when RM accepted the mistake, right?